One ~Kagayaku Kisetsu e~Similar to what were later Key works, but less good. The main idea isn't bad and is very Key, but it isn't developed enough. They learned later.
Robotics;Notes DaSHThe majority of the content is mediocre, but you get some good after stories for Robot Club members, Sci-ADV returning characters (very minor) cameos, and the final route is epic too. Worth reading if you're a fan.
Highway BlossomsNice story about a grieving girl meeting her (female) partner, the ups and downs of it, and traveling through the North American West.
Kono Yo no Hate de Koi o Utau Shoujo YU-NOI played Spike Chunsoft's remake. Well, mixing an eroge approach (the original game had H scenes and all), with a sci-fi story about parallel worlds doesn't produce an outstanding game.
Summer PocketsNot quite as good as Key's traditional games; it tries to be a nakige, but it has other elements. The drama is uneven. But nice effort.
TenkiameGet it for the sex romp, it makes about 66% of the game. This game literally has no plot, but understandable due to its nature (fox girl fetish) and short duration (about 10 hours).
Gyakuten Saiban 6Superb trial simulator, with excellent animation and presentation. And it's actually fun... but I played with a guide.
Shuukaku no Juunigatsu ~Fuyu~Very long, but it's a bit different from your regular moege; and no explicit H. Some characters are pretty cool, I liked the squirrel.
Hakuouki ~Shinsengumi Kitan~Nice stories set in the Bakumatsu period, the fall of shogunate Japan and the advent of the Empire of Japan. Small supernatural element but mostly samurai and historic drama.
NekoMikoVanilla nukige, I say avoid all of these games with priestesses or furry priestesses altogether. Unless you're into it!
Yurinate!For P-P aficionados. It can get better though.
Sanoba WitchThe regular Yuzusoft offering, with supernatural element. Maybe too long.